Network.MQTT.Client

An MQTT protocol client, based on the 3.1.1 specification: http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html

Configuring the client.

data MQTTConfig

Configuration for setting up an MQTT client.

Constructors

MQTTConfig

Fields

• _hostname :: String

  Host to connect to.

• _port :: Int

  Port number.

• _connID :: String

  Unique connection ID (required).

• _username :: Maybe String

  Optional username.

• _password :: Maybe String

  Optional password.

• _cleanSession :: Bool

  False if a session should be reused.

• _lwt :: Maybe LastWill

  LastWill message to be sent on client disconnect.

• _msgCB :: Maybe (Topic -> ByteString -> IO ())

  Callback for incoming messages.

data MQTTClient

The MQTT client. A client may be built using either runClient or runClientTLS. For example:

  mc <- runClient mqttConfig{}
  publish mc "some/topic" "some message" False

data QoS

QoS values for publishing and subscribing.

Constructors

QoS0

QoS1

QoS2

Instances

Bounded QoS

Defined in Network.MQTT.Types

Methods

minBound :: QoS

maxBound :: QoS

Enum QoS

Defined in Network.MQTT.Types

Methods

succ :: QoS -> QoS

pred :: QoS -> QoS

toEnum :: Int -> QoS

fromEnum :: QoS -> Int

enumFrom :: QoS -> [QoS]

enumFromThen :: QoS -> QoS -> [QoS]

enumFromTo :: QoS -> QoS -> [QoS]

enumFromThenTo :: QoS -> QoS -> QoS -> [QoS]

Eq QoS

Defined in Network.MQTT.Types

Methods

(==) :: QoS -> QoS -> Bool

(/=) :: QoS -> QoS -> Bool

Show QoS

Defined in Network.MQTT.Types

Methods

showsPrec :: Int -> QoS -> ShowS

show :: QoS -> String

showList :: [QoS] -> ShowS

type Topic = Text

Topic is a type alias for topic values.

mqttConfig :: MQTTConfig

A default MQTTConfig. A _connID should be provided by the client in the returned config, but the defaults should work for testing.

mkLWT :: Topic -> ByteString -> Bool -> LastWill

A convenience method for creating a LastWill.

data LastWill

An MQTT Will message.

Constructors

LastWill

Fields

• _willRetain :: Bool
• _willQoS :: QoS
• _willTopic :: ByteString
• _willMsg :: ByteString

Instances

Eq LastWill

Defined in Network.MQTT.Types

Methods

(==) :: LastWill -> LastWill -> Bool

(/=) :: LastWill -> LastWill -> Bool

Show LastWill

Defined in Network.MQTT.Types

Methods

showsPrec :: Int -> LastWill -> ShowS

show :: LastWill -> String

showList :: [LastWill] -> ShowS

Running and waiting for the client.

runClient :: MQTTConfig -> IO MQTTClient

Set up and run a client from the given config.

runClientTLS :: MQTTConfig -> IO MQTTClient

Set up and run a client connected via TLS.

waitForClient :: MQTTClient -> IO (Either SomeException ())

Wait for a client to terminate its connection.

disconnect :: MQTTClient -> IO ()

Disconnect from the MQTT server.

General client interactions.

subscribe :: MQTTClient -> [(Topic, QoS)] -> IO [Maybe QoS]

Subscribe to a list of topics with their respective QoSes. The accepted QoSes are returned in the same order as requested.

unsubscribe :: MQTTClient -> [Topic] -> IO ()

Unsubscribe from a list of topics.

publish

Arguments

:: MQTTClient

-> Topic

Topic

-> ByteString

Message body

-> Bool

Retain flag

-> IO ()

Publish a message (QoS 0).

publishq

Arguments

:: MQTTClient

-> Topic

Topic

-> ByteString

Message body

-> Bool

Retain flag

-> QoS

QoS

-> IO ()

Publish a message with the specified QoS.